This invention relates to a window sash positioner and more particularly to such a positioner which is adapted to retain a window sash at any selected position at it is moved relative to the side members of its window frame.
Heretofore in the art to which my invention relates, many devices have been proposed for retaining a window sash at selected positions relative to its window frame. Such devices have not only been complicated in structure and expensive to manufacture, but many of such devices can cause damage to the components of a window as the sash is raised or lowered and secured in selected positions along the window frame. U.S. Pat. No. 293,310 to Clements and U.S. Pat. No. 1,715,990 to Chaffee disclose screw-like members which are employed to retain the window sash at selected positions. U.S. Pat. Nos. 336,932 to McCall, 2,612,398 to Miller and 3,905,626 to Myers all disclose devices which are adapted for pivotal movement into and out of locking position whereby the window sash is locked at a selected position.
An object of my invention is to provide a window sash positioner which includes a movable locking element having a contact surface adapted to move into and out of engagement with an adjacent side member of a window frame with the contact surface facing the adjacent side member of the window frame and extending parallel thereto at all times as the contact surface moves into and out of engagement with the adjacent side member, thus providing maximum contact area between the locking element and the adjacent side member.
Another object of my invention is to provide a positioner for a movable window sash which is extremely simple of construction, economical of manufacture, and one which may be readily installed on conventional window frames having spaced apart side members with a window sash adapted for movement relative thereto.